It is important to remember that the spore counts presented below are intended to show daily trends in spore production and do not necessarily indicate inoculum pressure in your field(s). Spore production can vary from field to field, and inoculum pressure tends to be higher:

in older fields with a history of ergot in the previous season

in new fields planted next to established fields with a history of ergot

in fields with high numbers of sclerotia (for context, KBG1 and PRG1 are artificially-infested fields at COARC and HAREC, respectively)

when air temperatures are between 50 and 80°F

after precipitation or rain events

It is recommended that growers scout fields as grass seed crops approach anthesis.

Protective fungicides should be applied prior to the onset of anthesis to protect unfertilized flowers from infection.

A predictive model for ergot ascospores was recently developed for the Lower Columbia Basin of Oregon.

The model uses accumulated degree-days (beginning January 1, with a base temperature of 50°F and upper threshold temperature of 77°F) to forecast when ascospores are likely to be present.

According to the model, most ascospores are produced in the Lower Columbia Basin when accumulated degree-days are between 414 and 727.Accumulated degree-days as of May 10 were 387 in Hermiston, OR (black solid line).

At this time in 2017, accumulated degree-days were 302 (orange dotted line). Based on weather forecasts, the degree-day model will reach 414 over the weekend.

Ergot ascospores have been detected in the Columbia Basin at spore trap sites KBG4 (a commercial Kentucky bluegrass field near Paterson, WA) and in Central Oregon KBG1 (an artificially-infested Kentucky bluegrass field at the OSU Central Oregon Agricultural Research Center).

It is recommended that growers scout fields as grass seed crops approach anthesis.

Protective fungicides should be applied prior to the onset of anthesis to protect unfertilized flowers from infection.